Cementitious composition having a low co 2 footprint, good workability, and good very early and late strength formation

Abstract

A cementitious binder composition comprising 20-95 wt.-% of at least one supplementary cementitious material, 0.01-59 wt.-% of at least one cement clinker, 1-20 wt.-% of at least one sulfate source, 0.5-30 wt.-% of at least one calcium and / or magnesium source, 0.1-5 wt.-% of at least one soluble carbonate source, 0.001-3 wt.-% of at least one ettringite formation controller, and 0.001-5 wt.-% of at least one accelerator.

Description

[0001] BASF SE 240963W001

[0002] 1 B19191WO

[0003] Cementitious Composition having a low CO2Footprint, good Workability, and good Very Early and Late Strength Formation

[0004] Technical Field of the Invention

[0005] The present invention relates to a SCM-based construction composition for, e.g. application as precast concrete, ready mix concrete and dry mortars, with low CO2footprint, good workability, and very high early (5 h) and late strength (28 d).

[0006] Background of the Invention

[0007] Concrete is the globally most widely used construction material. Concrete is a composite material of a binding medium having particles or fragments of aggregate embedded therein. In most construction concretes currently employed, the binding medium is formed from a mixture of a hydraulic cement and water.

[0008] Prefabricated elements of concrete, such as modular building structures, are obtained by mixing materials including a cement, an aggregate, water, and a dispersant, molding in various molds, and curing. Because the mold is repeatedly used many times, from the viewpoint of productivity and for enhancing the turnover rate of the mold, it is important for the concretes to exhibit high very early strength. Likewise, to ensure sufficient time for processing the concrete, it is advantageous to have a certain workability window, which allows for working the concrete before reaching very early strength. Ideally, a combination between a broad workability window with high very early strength is achieved.

[0009] Most hydraulic cements employed today are based upon Portland cement clinker. Portland cement clinker is made primarily from certain clay minerals, limestone, quartz sand and iron ore, in a high temperature process that drives off carbon dioxide and chemically combines the primary ingredients into new compounds. Sulfate sources are typically added during the grinding of the cement clinker to regulate the reaction of C3A. Because carbon dioxide is generated by both the cement production process itself, as well as by energy plants that generate power to run the production process, cement production is currently a leading source of carbon dioxide atmospheric emissions. The production of ordinary Portland cement (OPC) is responsible for a significant part of global CO2emission (~818 kg C02 / ton). For decades, the raw material and high burning temperatures (up to 1450 °C) for the production of OPC have not changed. Hence, CO2emission by OPC based cements are still high.

[0010] Hence, generally, constructing materials having low CO2emissions are of interest. Aluminate cement (CAC) and sulfoaluminate cement (CSA) can provide good very early strength with lower CO2emission, but proper retardation and activation is needed. Supplementary cementitious materials (SCMs) have been described as having lower CO2emissions. However, as SCMs are also known for having low reactivity, the use of large volumes of SCMs in cementitious binders is limited.

[0011] Thermodynamically, if cement clinker (including OPC, CAC, CSA or other cement clinker phases) and SCMs reach full potential to produce calcium (aluminate) silicate hydrate (C-(A)-S- H) and ettringite, a low clinker cementitious binder can theoretically be realized with less overall CO2emission and proper performance. However, due to the different reaction processes of different cement clinker phases and the different types of SCMs, it is not easy to find a balance between high very early and late strength development and a respectively broad workability window defined by the setting time and the workability (for instance spread loss). Especially when high volumes of SCM, such as activated clay or natural pozzolan, or recycled concrete fines are used in the cementitious material, maintaining a proper workability is extremely challenging.

[0012] Achieving adequate very early strength in cementitious systems with high volumes of SCM is challenging due to their slow reaction and the reduced cement clinker content. The extra workability challenge coming from the SCM further hinders the application of such a binder in the field.

[0013] WO 2022 / 043348 A1 and WO 2022 / 043349 A1 are directed to a similar problem, i.e., to reduce the carbon footprint of construction compositions, and discloses a cement-reduced construction composition comprising cementitious binder, a fine material, a sulfate source, a soluble carbonate source, and an ettringite formation controller. However, the composition has the problem that the balance between setting time and early strength formation is not ideal. Either early strength formation is reduced, or the setting times are too short. BASF SE 240963W001

[0014] 2 B19191WO

[0015] WO 2022 / 229432 A1 describes the compositions comprising 1-30 wt.-% OPC and / or lime, 1- 40 wt.-% GGBFS, and at least one pozzolanic material in the range of from 20 wt.-% to 50 wt.- %. However, these compositions have the problem of poor very early and late strength formation.

[0016] Summary of the Invention

[0017] It is therefore an object of the present invention to provide a cementitious binder composition having low CO2footprint but at the same time a good workability, high very early and high late strength.

[0018] It has been surprisingly found that this object is achieved by a cementitious binder composition comprising 20-95 wt.-% of at least one supplementary cementitious material, 0.01-59 wt.% cement clinker, 1-20 wt.-% of at least one sulfate source, 0.5-30 wt.-% of at least one calcium and / or magnesium source, 0.1-5 wt.-% of at least one soluble carbonate source, 0.001-3 wt.-% of at least one ettringite formation controller, and 0.001-5 wt.-% of at least one accelerator.

[0019] One advantage of the present invention is that the usage of SCM materials results in significantly reduced CO2footprint.

[0020] Without wishing to be bound by theory it is believed that the very early strength formation is mainly connected to the ettringite formation via the reactive aluminate clinker phases and / or the reactive alumina in the SCMs together with calcium sulfate source and / or calcium source. Upon hydration of a cementitious system, ettringite is generated in a rapid reaction. Ettringite is a calcium aluminum sulfate compound having the formula Ca6AI2(SO4)3* 32 H2O or alternatively 3 CaO * AI2O3* 3 CaSO4* 32 H2O. This reaction is among others responsible for the setting and the development of early compressive strength of the cementitious composition. Ettringite forms as long needle-like crystals. The newly formed needle-like ettringite crystals, however, tend to deteriorate the workability or flowability of the cementitious composition if such formation is not well controlled. In addition, ettringite contains 32 moles of water in its stoichiometric formula. This means that upon ettringite formation, a significant amount of water is bound in the solid crystals. A further quantity of water is adsorbed at the newly developing ettringite surfaces. As a result, the flowability of the composition is reduced. Thus, it is an advantage of the present invention that the ettringite formation is controlled to achieve a longer setting time window with small spread loss (or flow loss) thereby achieving similar workability across the setting time window.

[0021] On the other hand, the late strength formation is connected with the pozzolanic and / or hydraulic reaction from the SCMs and / or the other clinker phases such as C3S and C2S. Hence, by controlling the ettringite formation by efficiently retarding the high alumina system an optimal strength balance can be achieved.

[0022] Hence, it was surprisingly found that in the composition of the present invention the ettringite formation controller is able to retard the very early ettringite formation without or very limited retarding the later silicate reaction, and / or the hydraulic and / or pozzolanic reaction. Another advantage of the present invention is that the ettringite formation controller not only retards the system to a required workability window, but also generally enhances the workability during this window without changing the flow behavior significantly. The use of accelerators acts partially on the formation of ettringite, but primarily enhances the early and late reaction of SCM and other clinker phases such as C3S and C2S, thus contributing to overall strength enhancement.

[0023] Definitions

[0024] Before describing in detail exemplary embodiments of the present invention, definitions which are important for understanding the present invention are given.

[0025] The term ‘very early strength formation' denotes the strength formed in the first 5 h after mixing the cementitious composition together with water. The exact time point of the very early strength can range from less than 1 hour to a couple of hours depending on the application. This time typically comes shortly after the setting of cement paste / mortar / concrete was triggered due to ettringite formation. The occurrence of the very early strength can be controlled by the dosage of the ettringite controller.

[0026] The term ‘early strength formation' denotes the strength formed in the first 1 d after mixing the cementitious composition together with water. BASF SE 240963W001

[0027] 3 B19191WO

[0028] The term ‘late strength formation' denotes the strength formed in the first 28 d after mixing the cementitious composition together with water.

[0029] The term ‘supplementary cementitious materials (SCM)’ as used herein denotes powdered materials having an R3reactivity after 7 days total heat release equal to or more than 50 J / g SCM measured according to ASTM 1897 test. Preferred SCMs are selected from the list consisting of activated clay (i.e. calcined clay or activated clay by means of mechanical and / or chemical way), GGBFS, electric arc furnace slag (EAF), basic oxygen furnace slag (BOF), fly ash, natural pozzolan, rice husk ashes, recycled concrete fine, perlite, zeolite, or other synthetic and or processed reactive materials. The reactivity of SCMs is generally measured according to ASTM 1897.

[0030] The term 'filler1as used herein denotes compounds such as limestone powder, vaterite powder or quartz powder having a R3reactivity at 7 days of lower than 50 J / g SCM measured according to ASTM 1897.

[0031] The mineralogical phases are indicated by their usual name followed by their cement notation. The primary compounds are represented in the cement notation by the oxide varieties: C for CaO, S for SiO2, A for AI2O3, F for Fe2O3, $ for SO3, H for H2O; this notation is used throughout.

[0032] The term ‘cement clinker’ as used herein denotes a compound selected from the list consisting of ordinary Portland cement clinker (C3S, C2S, C3A, C4AF), calcium aluminate cement clinker (main phases CA, CI2A7, CA2, Q-phase), calcium sulfoaluminate cement clinker (main phases ye’elimite), or mixtures thereof. The cement clinker can also be other types of clinker, such as alite sulfoaluminate cement clinker and belite ferrite sulfoaluminate cement clinker, as soon as clinker phases are present in the compound. The cement clinker phase can be crystalline, amorphous, or partially crystalline and amorphous, wherein these modifications can be characterized by X-ray powder diffraction. The total clinker content is defined as the sum of these main cement clinker phases in the composition. The cement clinker can be further classified in two categories: silicate phases and aluminate phases. Silicate phases are phases mainly composed of calcium and silicon such as C3S, C2S, C5S2$ (mineral name Ternesite with chemical formula 5 CaO * 2 SiO2* SO3). Aluminate clinker phases are phases mainly composed of calcium, aluminum, or iron such as C3A, C4AF, CA, CI2A7, CA2, C4A3$ (ye’elimite), Q-phases etc.

[0033] The term ‘Portland cement' as used herein denotes any cement compound containing Portland clinker, especially CEM I within the meaning of standard EN 197-1 , paragraph 5.2. A preferred cement is ordinary Portland cement (OPC) according to EN 197-1. The phases constituting Portland cement mainly are alite (C3S), belite (C2S), tricalcium aluminate (C3A), calcium ferroaluminate (C4AF) and other minor phases. Commercially available OPC may either contain calcium sulfate (< 7 wt.-%) or is essentially free of calcium sulfate (< 1 wt.-%).

[0034] Mineralogical phases in cement are typically determined using quantitative X-ray diffraction (XRD).

[0035] The term “binder composition" as used herein denotes a composition comprising a binder such as Portland cement. The binder composition according to the present invention comprises fine granulates, i.e. granulates whose diameter is less than 0.125 mm.

[0036] The term ‘sulfate source' as used herein denotes a compound selected from the list consisting of anhydrite, hemihydrate, gypsum, Na2SO4, K2SO4, AI2(SO4)3or mixtures thereof.

[0037] The term ‘ettringite formation controller' as used herein denotes a compound, which is able to control the ettringite formation thereby achieving a certain target early strength and / or late strength of the composition. Preferably, the ettringite formation controller has a retarding effect in particular during very early strength formation.

[0038] The term ‘accelerator' as used herein denotes a compound, which is able to accelerate early strength and / or late strength formation of the composition.

[0039] As used in this specification and in the appended claims, the singular forms of ‘a’ and ‘an' also include the respective plurals unless the context clearly dictates otherwise. In the context of the BASF SE 240963W001

[0040] 4 B19191WO present invention, the terms ‘about’ and ‘approximately’ denote an interval of accuracy that a person skilled in the art will understand to still ensure the technical effect of the feature in question. The term typically indicates a deviation from the indicated numerical value of ±10 %, preferably ±8 %, more preferably ±5 %, even more preferably ±2 %. It is to be understood that the term ‘comprising’ and ‘encompassing’ is not limiting. For the purposes of the present invention the term ‘consisting of is considered to be a preferred embodiment of the term ‘comprising of. If hereinafter a group is defined to comprise at least a certain number of embodiments, this is meant to also encompass a group which preferably consists of these embodiments only. Furthermore, the terms ‘first’, ‘seconcf, ‘third: or ‘(a)', ‘(b)’ , ‘(c)’, ‘(d)’ etc. and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. In case the terms ‘first’, ‘seconcf, ‘third’ or ‘(a)’, ‘(b)’, ‘(c)’, ‘(d)’, ‘i’, 7 / ’ etc. relate to steps of a method or use or assay there is no time or time interval coherence between the steps, i.e. the steps may be carried out simultaneously or there may be time intervals of seconds, minutes, hours, days, weeks, months or even years between such steps, unless otherwise indicated in the application as set forth herein above or below. It is to be understood that this invention is not limited to the particular methodology, protocols, reagents etc. described herein as these may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention that will be limited only by the appended claims. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art.

[0041] As used herein the term ‘does not comprise', ‘does not contain', or ‘free of means in the context that the composition of the present invention is free of a specific compound or group of compounds, which may be combined under a collective term, that the composition does not comprise said compound or group of compounds in an amount of more than 0.8 % by weight, based on the total weight of the composition. Furthermore, it is preferred that the composition according to the present invention does not comprise said compounds or group of compounds in an amount of more than 0.5 % by weight, preferably the composition does not comprise said compounds or group of compounds at all.

[0042] When referring to compositions and the weight percent of the therein comprised ingredients it is to be understood that according to the present invention the overall amount of ingredients does not exceed 100% (± 1% due to rounding).

[0043] Detailed Description of the Invention

[0044] As set out above, the present invention relates to a cementitious binder composition comprising

[0045] 20-95 wt.-% of at least one supplementary cementitious material,

[0046] 0.01-59 wt.% cement clinker,

[0047] 1-20 wt.-% of at least one sulfate source,

[0048] 0.5-30 wt.-% of at least one calcium and / or magnesium source,

[0049] 0.1-5 wt.-% of at least one soluble carbonate source,

[0050] 0.001-3 wt.-% of at least one ettringite formation controller, and

[0051] 0.001-5 wt.-% of at least one accelerator.

[0052] It has been found that this composition can achieve high early strength and high late strength at advantageous setting times and low spread loss, thereby achieving an improved workability window. The composition furthermore has a significantly reduced CO2footprint in comparison to compositions having higher cement clinker content such as OPC.

[0053] Cementitious binder composition

[0054] The cementitious binder composition of the present invention has preferably an initial setting time in the range of from 60 to 150 min, preferably from 60 to 100 min. The setting time can also be adjusted by adjusting the dosage of the ettringite controller to a window from a few minutes to a few hours when needed. Moreover, the cementitious binder composition preferably has a spread loss (or flow loss) from 5 to 30 min of not higher than 21 %. This ensures that a sufficiently large time window is present to work the composition without having a significant change in flowing properties thereof. The open window for the spread can also be adjusted via BASF SE 240963W001

[0055] 5 B19191WO adjusting the setting via dosage of ettringite controller. Ideally a window of 120 to 180 min can be achieved, which is typically required by ready mix concrete.

[0056] Furthermore, the cementitious binder composition of the present invention has a GWP less than 800 kg C02 / ton dry binder, preferably less than 750 kg C02 / ton dry binder, more preferably less than 700 kg C02 / ton dry binder, even more preferably less than 600 kg C02 / ton dry binder, and most preferably less than 550 kg C02 / ton dry binder.

[0057] The cementitious binder composition of the present invention has a very early strength (after 5 h) in the range of from 2 to 6 MPa, preferably in the range of from 3.3 to 5.8 MPa, and most preferably in the range of from 5.0 to 5.7 MPa. Likewise, the cementitious binder composition of the present invention has an early strength (after 1 d) in the range of from 2 to 22 MPa, preferably in the range of from 4 to 19 MPa, and most preferably in the range of from 8.0 to 18 MPa. Preferably, the cementitious binder composition of the present invention has a late strength (after 28 d) in the range of from 28 to 55 MPa, more preferably in the range of from 33 to 50 MPa, and most preferably in the range of from 35 to 48 MPa. The strength tests were performed according to EN 196-1.

[0058] Supplementary cementitious material

[0059] The at least one supplementary cementitious material is present in the cementitious binder composition according to the present invention in an amount in the range of from 20-95 wt.-%, preferably in the range of from 21 to 80 wt.-%, more preferably in the range of from 22 to 50 wt.- %, and most preferably in the range of from 23 to 45 wt.-%, with respect to the total weight of the cementitious binder composition. If the amount of the at least one supplementary cementitious material is too low, the CO2footprint of the composition becomes unfavorable. If it is too high, the very early strength will be significantly decreased.

[0060] Preferably, the at least one supplementary cementitious material is a powdered material having an R3reactivity after 7 days total heat release ore equal to or more than 50 J / g SCM measured according to ASTM 1897 test. More preferably, the at least one supplementary cementitious material is selected from the list consisting of activated clay, preferably calcined clay, ground granulated blast-furnace slag (GGBFS), electric arc furnace slag (EAF), basic oxygen furnace slag (BOF), fly ash, natural pozzolan, metakaolin, rice husk ashes, recycled concrete fine, perlite, zeolite, silica fume, or other synthetic and / or processed waste reactive materials.

[0061] More preferably, the at least one supplementary cementitious material comprises at least one hydraulic supplementary cementitious material and at least one pozzolanic supplementary cementitious material. Preferred hydraulic supplementary cementitious materials are selected from the list consisting of ground granulated blast-furnace slag (GGBFS), electric arc furnace slag (EAF), basic oxygen furnace slag (BOF), recycled concrete fine, and mixtures thereof and / or the at least one pozzolanic supplementary cementitious material is selected from the list consisting of activated clay, preferably calcined clay, fly ash, natural pozzolan, metakaolin, rice husk ashes, recycled concrete fine, perlite, zeolite, and mixtures thereof.

[0062] Cement clinker

[0063] The cementitious binder composition comprises at least one cement clinker in the range of from 0.01 to 59 wt.-% with respect to the total weight of the cementitious binder composition. Preferably, the at least one cement clinker is present in the cementitious binder composition in an amount in the range of from 5 to 50 wt.-%, more preferably in the range of from 10 to 35 wt.- %, with respect to the total weight of the cementitious binder composition. If the content of cement clinker is too high, the CO2footprint of the composition becomes unfavorable.

[0064] The at least one cement clinker is a crystalline and / or amorphous cement clinker in the range of CEM III to CEM IV, preferably is selected from the list consisting of Portland cement clinker (C3S, C2S, C3A, C4AF), calcium aluminate cement clinker (main phases CA, CI2A7, CA2, Ciphase), calcium sulfoaluminate cement clinker (main phases ye’elimite), alite sulfoaluminate cement clinker, belite ferrite sulfoaluminate cement clinker, and mixtures thereof, more preferably is selected from the list consisting of Portland cement clinker (C3S, C2S, C3A, C4AF), calcium aluminate cement clinker (main phases CA, CI2A7, CA2, Q-phase), calcium sulfoaluminate cement clinker (main phases ye’elimite), and mixtures thereof, even more preferably is selected from the list consisting of Portland cement clinker (C3S, C2S, C3A, C4AF), calcium sulfoaluminate cement clinker (main phases ye’elimite), and mixtures thereof, and most preferably is Portland cement clinker (C3S, C2S, C3A, C4AF). BASF SE 240963W001

[0065] 6 B19191WO

[0066] In a first especially preferred embodiment of the present invention, the cementitious binder composition comprises the cement clinker in an amount in the range of from 5 to 10 wt.-%, preferably 8 to 12 wt.-%. In this first especially preferred embodiment of the invention, the cement clinker is preferably calcium sulfoaluminate cement clinker.

[0067] In a second especially preferred embodiment of the present invention, the cementitious binder composition comprises the cement clinker in an amount in the range of from 25 to 35 wt.-%, preferably 28 to 32 wt.-%. In this second especially preferred embodiment of the invention, the cement clinker is preferably Portland cement clinker.

[0068] In a third especially preferred embodiment of the present invention, the cementitious binder composition comprises the cement clinker in an amount in the range of from 30 to 40 wt.-%, preferably 32 to 37 wt.-%. In this first especially preferred embodiment of the invention, the cement clinker is preferably a mixture from Portland cement clinker and calcium sulfoaluminate cement clinker, preferably in a weight ratio in the range of from 5:1 to 7:1 , preferably in a 6:1 weight ratio.

[0069] Sulfate source

[0070] The at least one sulfate source is present in an amount in the range of from 1 to 20 wt.-%, preferably in the range of from 1 to 18 wt.-%, more preferably in the range of from 5 to 15 wt.-%, and most preferably in the range of from 8 to 12 wt.-%, with respect to the total weight of the cementitious binder composition.

[0071] The at least one sulfate source is used to promote the aluminate reaction to form maximum amount of ettringite and to induce the optimum hydration of C3S to occur. Hence, the amount of the at least one sulfate source influences the hydration, rheology, setting, phase assemblage, Dorosity distribution, and strength in the cementitious binder composition. If the amount of the at east one sulfate source is too low, the formation of ettringite is not proper and the potential of the reactive aluminate is not activated. Consequently, a strong delay in the silicate / SCM reaction can be observed. If the amount of the at least one sulfate source is too high, increased expansion can be observed. Preferably, the at least one sulfate source is selected from the list consisting of calcium sulfate anhydrite, calcium sulfate hemihydrate, gypsum, sodium sulfate, potassium sulfate, aluminum sulfate, and mixtures thereof. Most preferably, the at least one sulfate source is calcium sulfate anhydrite or sodium sulfate.

[0072] Calcium or magnesium source

[0073] The cementitious binder composition according to the invention comprises the at least one calcium and / or magnesium source in an amount in the range of from 0.5 to 30 wt.-%, preferably in the range of from 1 to 20 wt.-%, more preferably in the range of from 5 to 15 wt.-%, and most preferably in the range of from 8 to 12 wt.-%, with respect to the total weight of the cementitious binder composition.

[0074] The at least one calcium and / or magnesium source can be selected from the list consisting of calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide and the mixture thereof, preferable is selected from calcium hydroxide or magnesium hydroxide. The at least one calcium and / or magnesium source is used to enhance the initial ettringite formation and the overall SCM reaction especially for the pozzolanic SCM. This can give better very early age and late strength by guaranteeing that the initial ettringite formation and the late SCM reaction work.

[0075] Soluble carbonate source

[0076] The cementitious binder composition according to the present invention comprises the at least one soluble carbonate source in an amount up to 5 wt.-%, preferably in the range of from 0.2 to 5 wt.-%, more preferably in the range of from 0.5 to 3 wt.-%, even more preferably in the range of from 0.7 to 1.5 wt.-%, and most preferably in the range of from 0.9 to 1.1 wt.-%, with respect to the total weight of the cementitious binder composition.

[0077] Without being bound by theory, it is assumed that the presence of the at least one soluble carbonate source ensures that the mixing water is initially highly concentrated in carbonate ions. Carbonate ions are believed to first inhibit and then promote the crystallization of ettringite. The at least one soluble carbonate source may be an inorganic carbonate having an aqueous solubility of 0.1 g / L or more. The aqueous solubility of the inorganic carbonate is determined in water at pH 7 and 25 °C. These characteristics are well known to those skilled in the art. BASF SE 240963W001

[0078] B19191WO

[0079] The inorganic carbonate is intended to mean a salt of carbonic acid, i.e., a salt which is characterized by the presence of a carbonate ion (CO32j and / or hydrogen carbonate ion (HCO3_)•

[0080] The inorganic carbonate may be suitably selected from alkali metal carbonates such as sodium carbonate or lithium carbonate, and alkaline earth metal carbonates satisfying the required aqueous solubility, such as potassium carbonate. Further suitable inorganic carbonates include carbonates of nitrogenous bases such as guanidinium carbonate und ammonium carbonate.

[0081] Hence, the at least one soluble carbonate source is preferably selected from the list consisting of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, amorphous calcium carbonate, vaterite, injected carbon dioxide, aqueous solution of carbon dioxide, or mixtures thereof. The product of other methods such as mixing under CO2atmospheric conditions, thereby forcing some CO2into the solution thus forming C032or HCO3_, is also considered as a soluble carbonate source. More preferably, the at least one soluble carbonate source is selected from the list consisting of sodium carbonate, sodium bicarbonate, potassium carbonate, and mixtures thereof. Most preferably, the at least one soluble carbonate source is sodium carbonate and / or sodium bicarbonate.

[0082] Alternatively, the carbonate source is selected from organic carbonates. Organic carbonate denotes an ester of a carbonic acid. The organic carbonate is hydrolyzed in the presence of the cementitious system to release carbonate ions. In an embodiment, the organic carbonate is selected from ethylene carbonate, propylene carbonate, glycerol carbonate, dimethyl carbonate, di(hydroxyethyl)carbonate or a mixture thereof, preferably ethylene carbonate, propylene carbonate, and glycerol carbonate or a mixture thereof, and in particular ethylene carbonate and / or propylene carbonate. Mixtures of inorganic carbonates and organic carbonates can as well be used.

[0083] Ettringite formation controller

[0084] The cementitious binder composition according to the present invention comprises the at least one ettringite formation controller in an amount in the range of from 0.001 to 3wt.-%, preferably in the range of from 0.1 to 2.0 wt.-%, more preferably in the range of from 0.2 to 1.0 wt.-%, and most preferably in the range of from 0.3 to 0.6 wt.-%, with respect to the total weight of the cementitious binder composition.

[0085] Moreover, the at least one ettringite formation controller is preferably selected from the list consisting of a glyoxylic acid, a glyoxylic acid salt, a glyoxylic derivative, sodium gluconate, alpha-sulfoglycolate, citric acid, salts of citric acid, tartaric acid, salts of tartaric acid, sugar, salts of sugar, phosphate, phosphonate, zinc oxide, and mixtures thereof, preferably comprises a first ettringite formation controller selected from the list consisting of a glyoxylic acid, a glyoxylic acid salt, a glyoxylic derivative, and mixtures thereof and a second ettringite formation controller selected from the list consisting of sodium gluconate, alpha-sulfoglycolatecitric acid, salts of citric acid, tartaric acid, salts of tartaric acid, sugar, salts of sugar, phosphate, phosphonate, zinc oxide, and mixtures thereof, most preferably comprises poly[urea-alt-(glyoxylic acid)] (PUG) and disodium or dipotassium alpha-sulfoglycolate.

[0086] In an even more preferred embodiment of the present invention, the ettringite formation controller is an ettringite formation controller comprising a glyoxylic acid condensate, glyoxylic acid adduct, or glyoxylic acid, and mixtures thereof. It is believed that the glyoxylic acid condensate, glyoxylic acid adduct, and glyoxylic acid suppresses the formation of ettringite from the aluminate phases originating from the cementitious binder by stabilizing the aluminate phases and thereby slowing down the dissolution of the aluminate phases.

[0087] Glyoxylic acid has in general a structure according to formula I: BASF SE 240963W001

[0088] B19191WO

[0089] As used herein, salts of glyoxylic acid include the alkali, alkaline earth, zinc, iron, aluminum, ammonium, and phosphonium salts of glyoxylic acid. As used herein, addition products of glyoxylic acid or salts thereof refer to products, which are obtainable by reacting a nucleophilic compound with the a-carbonyl group of glyoxylic acid, so as to obtain a-substituted a-hydroxy- acetic acid or a salt thereof as an adduct. As used herein, condensation products of glyoxylic acid or salts thereof refer to condensation products obtainable by reacting a compound containing at least one amino or amido group with the a-carbonyl group of glyoxylic acid, such that water is set free. Examples of compounds containing at least one amino or amido group include urea, thiourea, melamine, guanidine, acetoguanamine, benzoguanamine and other acyl- guanamines, polyvinylamine and polyacrylamide.

[0090] In one embodiment, the addition product of glyoxylic acid under the ettringite formation controller is a bisulfite adduct of glyoxylic acid or a salt or a mixed salt thereof, wherein the bisulfite adduct preferably has the formula II (alpha-sulfoglycolate): wherein X is in each case independently selected from H or a cation equivalent Ka, wherein K is an alkali metal, alkaline earth metal, zinc, iron, aluminum, ammonium, or a phosphonium cation, and wherein a is 1 / n, wherein n is the valence of the cation. More preferably, X is H or Ka, wherein K is an alkali metal. Even more preferably K is lithium, sodium or potassium. It is to be understood that also mixed salts are possible. In a particularly preferred embodiment X is independently sodium or potassium or a mixture thereof.

[0091] The bisulfite adducts are commercially available or can be prepared by conventional methods which are known to the skilled person. See, e.g., WO 2017 / 212045 A1 for further details in this regard.

[0092] In another embodiment, the ettringite formation controller is glyoxylic acid or a salt thereof. Preferably, the ettringite formation controller is a compound of formula III: wherein X is selected from H or a cation equivalent Ka, wherein K is an alkali metal, alkaline earth metal, zinc, iron, aluminum, ammonium, or a phosphonium cation, and wherein a is 1 / n, wherein n is the valence of the cation. More preferably, X is H or Ka, wherein K is an alkali metal. Even more preferably K is lithium, sodium or potassium. It is to be understood that also mixed salts are possible. In a particularly preferred embodiment X is sodium or potassium or a mixture thereof.

[0093] In yet another embodiment, the ettringite formation controller is preferably a condensation product of glyoxylic acid or a salt thereof. More preferably, the ettringite formation controller is a compound selected from the group consisting of a melamine-glyoxylic acid condensate, a ureaglyoxylic acid condensate, a melamine-urea-glyoxylic acid condensate and a polyacrylamideglyoxylic acid condensate. Most preferably, the amine-glyoxylic acid condensate is a ureaglyoxylic acid condensate.

[0094] The amine-glyoxylic acid condensates are obtainable by reacting glyoxylic acid with a compound containing aldehyde-reactive amino or amido groups. The glyoxylic acid can be used as an aqueous solution or as glyoxylic acid salts, preferably glyoxylic acid alkaline metal salts. Likewise, the amine compound can be used as salt, for example as guanidinium salts. In general, the amine compound and the glyoxylic acid are reacted in a molar ratio of 0.5 to 2 BASF SE 240963W001

[0095] 9 B19191WO equivalents, preferably 1 to 1 .3 equivalents, of glyoxylic acid per aldehyde-reactive amino or amido group. The reaction is carried out at a temperature of 0 to 120 °C, preferably 25 to 105 °C, most preferably 30 to 50 °C. The pH value is preferably from 0 to 8. The viscous products obtained in the reaction can be used as such, adjusted to a desired solids content by dilution or concentration or evaporated to dryness by, e.g., spray-drying, drum-drying, or flashdrying.

[0096] In general, the amine-glyoxylic acid condensates have molecular weights in the range of from 500 to 25000 g / mol, preferably 1000 to 10000 g / mol, particularly preferred 1000 to 5000 g / mol. The molecular weight is measured by the gel permeation chromatography method (GPC) as indicated in detail in the experimental part.

[0097] Thus, in one embodiment, the ettringite formation controller is selected from a compound according to formula II, a compound according to formula III, and an amine-glyoxylic acid condensate selected from the group consisting of a melamine-glyoxylic acid condensate, an urea-glyoxylic acid condensate, a melamine-urea-glyoxylic acid condensate and a polyacrylamide-glyoxylic acid condensate; and mixtures thereof; wherein X is in each case independently selected from H or a cation equivalent Ka, wherein K is an alkali metal, alkaline earth metal, zinc, iron, aluminum, ammonium, or a phosphonium cation, and wherein a is 1 / n, wherein n is the valence of the cation.

[0098] In a preferred embodiment, the ettringite formation controller is selected from a compound according to formula II, a compound according to formula III, and an urea-glyoxylic acid condensate, and mixtures thereof, wherein X is in each case independently selected from H or a cation equivalent Ka, wherein K is an alkali metal, alkaline earth metal, zinc, iron, aluminum, ammonium, or a phosphonium cation, and wherein a is 1 / n, wherein n is the valence of the cation, and wherein preferably X is in each case independently selected from H and alkali metals, in particular from sodium, potassium, and mixtures thereof.

[0099] Most preferably, the ettringite formation controller is selected from an amine-glyoxylic acid condensate, preferably an urea-glyoxylic acid condensate, and an alpha-sulfoglycolate, preferably a disodium or dipotassium alpha-sulfoglycolate.

[0100] It has been found that these ettringite formation controller have a particularly high retarding effect during very early strength formation, but a significant lower retarding effect afterwards. This allows for a specifically well-defined control of the workability window.

[0101] The ettringite formation controller can be present as a solution or dispersion or powder, in particular an aqueous solution or dispersion. The solution or dispersion suitably has a solids content of 10 to 50% by weight, in particular 25 to 35% by weight. Alternatively, the ettringite formation controller can be present as a powder which is obtainable, e.g., by drum-drying, spray-drying or flash-drying. The ettringite formation controller may be introduced into the mixing water or introduced during the mixing of the mortar or concrete before addition of water. The ettringite formation controller can also be introduced in powder form.

[0102] Accelerator

[0103] The cementitious binder composition according to the present invention comprises the at least one accelerator in an amount (refer to solid content) in the range of from 0.001 to 5 wt.-%, preferably in the range of from 0.01 to 4.0 wt.-%, more preferably in the range of from 0.5 to 3.0 wt.-%, and most preferably in the range of from 1 .0 to 2.0 wt.-%, with respect to the total weight of the cementitious binder composition.

[0104] Preferably, the at least one accelerator is selected from the list consisting of nanoseeds, preferably selected from a calcium-silicate-hydrate (C-S-H)nanoseeds, silica nanoseeds, ettringite nanoseeds, calcium hydroxide nanoseeds, layered double hydroxides (LDH, hydrotalcite-like minerals) nanoseeds, and mixtures thereof, lithium carbonate, lithium hydroxide, glycerol, salts of glycerol, thiocyanate, metal formate, metal sulfamate, sulfates, wherein the sulfates are preferably selected from sodium sulfate, potassium sulfate, aluminum sulfate, lithium sulfate, and mixture thereof, nitrates, wherein the nitrates preferably are selected from sodium nitrate, potassium nitrate, calcium nitrate, magnesium nitrate, and mixtures thereof, chlorides, wherein the chlorides are preferably are selected from calcium chloride and lithium chloride, magnesium chloride, and mixtures thereof, alkanolamines, and mixtures thereof. Alkanolamines are preferably selected from the list consisting of triethanolamine (TEA), triisopropanolamine (TIPA), diisopropylamine (DIPA), diethanolamine (DEA), diethanolisopropanolamine (DEIPA), ethanol-diisopropanolamine (EDIPA), and mixtures thereof. BASF SE 240963W001

[0105] 10 B19191WO

[0106] In a more preferred embodiment, the at least one accelerator is selected from the list consisting of nanoseeds, preferably selected from a calcium-silicate-hydrate (C-S-H) nanoseeds, silica nanoseeds, ettringite nanoseeds, calcium hydroxide nanoseeds, layered double hydroxides (LDH, hydrotalcite-like minerals) nanoseeds, and mixtures thereof, thiocyanate, metal formate, metal sulfamate, sulfates, wherein the sulfates are preferably selected from sodium sulfate, potassium sulfate, aluminum sulfate, and mixture thereof, nitrates, wherein the nitrates preferably are selected from sodium nitrate, potassium nitrate, calcium nitrate, magnesium nitrate, and mixtures thereof, calcium chloride, magnesium chloride, and mixtures thereof.

[0107] In an even more preferred embodiment, the at least one accelerator is selected from the list consisting of nanoseeds, preferably selected from a calcium-silicate-hydrate (C-S-H) nanoseeds, silica nanoseeds, ettringite nanoseeds, calcium hydroxide nanoseeds, layered double hydroxides (LDH, hydrotalcite-like minerals) nanoseeds, and mixtures thereof.

[0108] A particularly preferred accelerator is a calcium-silicate-hydrate (C-S-H), preferably C-S-H nanoseeds. The calcium-silicate-hydrate can be preferably described with regard to its composition by the following empirical formula: a CaO, SiO2, b AI2O3, c H2O, d X, e W X is an alkali metal

[0109] W is an alkaline earth metal

[0110] 0.1 < a < 2 preferably 0.66 < a < 1.8 0 < b < 1 preferably 0 < b < 0.1 1 < c < 6 preferably 1 < c < 6.0 0 < d < 1 preferably 0 < d < 0.4 or 0.2 0 < e < 2 preferably 0 < e < 0.1

[0111] Calcium-silicate-hydrate can be obtained preferably by reaction of a calcium compound with a silicate compound, in presence of a water-soluble comb polymer which is suitable as plasticizer for hydraulic binders. Such products containing calcium-silicate-hydrate are for example described in WO 2010 / 026155 A1 , EP14198721 , WO 2014 / 114784, WO 2014 / 114782 or WO 2018 / 154012.

[0112] The calcium-silicate-hydrate may contain foreign ions, such as magnesium, aluminum, iron and / or transition metals preferably selected from the list consisting of Or, Mn, Fe, Co, Ni, Cu, and Zn. Hence, the calcium-silicate-hydrate may comprise transition silicate hydrates such as for examples described in EP 3 080 052. It should be noted that the present invention also works with pure transition silicate hydrates. However, they are less preferred as they are usually expensive.

[0113] C-S-H may be provided, e.g., as low-density C-S-H, C-S-H gel, or C-S-H seeds. CSH seeds having an average diameter of less the 10 pm, preferably less than 1 pm are preferred. C-S-H seeds in powdered form can also be used.

[0114] The water content of the calcium-silicate-hydrate in powder form, low-density C-S-H, or C-S-H seeds in powder form is preferably from 0.1 wt.-% to 5.5 wt.-% with respect to the total weight of the powder sample. Said water content is measured by putting a sample into a drying chamber at 80 °C until the weight of the sample becomes constant. The difference in weight of the sample before and after the drying treatment is the weight of water contained in the sample. The water content (%) is calculated as the weight of water contained in the sample divided with the weight of the sample.

[0115] The calcium-silicate-hydrate may preferably be provided as an aqueous suspension. The water content of the aqueous suspension is preferably from 10 wt.-% to 95 wt.-%, preferably from 40 wt.-% to 90 wt.-%, more preferably from 50 wt.-% to 85 wt.-%, in each case the percentage is given with respect to the total weight of the aqueous suspension sample. The water content is determined in an analogous way as described in the before standing text by use of a drying chamber.

[0116] It has been found that these accelerators have, in particular with the ettringite formation controller of the present invention, the advantage that the very early strength formation can be retarded to achieve a workability window large enough to allow good operation but ensure a quick strength formation after this window and still maintain very good late strength formation. BASF SE 240963W001

[0117] 11 B19191WO

[0118] Particularly advantageous in this sense is the combination of C-S-H nanoseeds as accelerator and an amine-glyoxylic acid condensate, preferably a urea-glyoxylic acid condensate, as ettringite formation controller. Another particularly advantageous combination is the combination of C-S-H nanoseeds as accelerator and an alpha-sulfoglycolate, preferably disodium alphasulfoglycolate or dipotassium alpha-sulfoglycolate, as ettringite formation controller.

[0119] Filler

[0120] Preferably, the cementitious binder composition comprises up to 20 wt.-% of at least one filler. More preferably, the at least one filler is present in the cementitious binder composition in an amount in the range of from 5 to 20 wt.-%, preferably in the range of from 15 to 20 wt.-%, and most preferably in the range of from 17 to 19 wt.-%, with respect to the total weight of the cementitious binder composition.

[0121] The at least one filler is preferably a material, more preferably powdered material, having an R3reactivity after 7 days of total heat release of less than 50 J / g SCM measured according to ASTM 1897. Most preferably, the at least one filler is selected from limestone powder or quartz powder.

[0122] Hence, usually, the filler is an inert material which essentially does not form hydration products. The filler may be selected from quartz, sand, marble, e.g., crushed marble, glass spheres, granite, basalt, limestone, sandstone, calcite, marble, serpentine, travertine, dolomite, feldspar, gneiss, alluvial sands, and mixtures thereof.

[0123] The packing density of the fillers should be as high as possible, and their particle size distribution ideally constitutes a fuller type sieve curve.

[0124] Filers may be classified by particle size. Fine aggregates, e.g., sand, generally have a diameter distribution of 150 pm to 5 mm. Coarse aggregates generally have a diameter distribution of more than 5 mm.

[0125] Dispersant

[0126] It is known that dispersants are added to aqueous slurries of hydraulic binders for improving their workability, i.e. kneadability, spreadability, sprayability, pumpability or flowability. Such admixtures are capable of preventing the formation of solid agglomerates, and of dispersing the particles already present as well as those newly formed by hydration, and in this way improving the workability. In order to convert the pulverulent binders into a freshly mixed processible form, substantially more mixing water is required than would be necessary for the subsequent hydration and hardening process. The voids formed in the concrete body by the excess of water, which subsequent y evaporates, lead to poor mechanical strength and resistance. In order to reduce the excess proportion of water at a predetermined processing consistency and / or to improve the workability at a predetermined water / binder ratio, admixtures are used which are generally referred to as water-reducing agents or plasticizers.

[0127] Hence, the cementitious binder composition according to the present invention preferably comprises at least one dispersant, wherein the at least one dispersant is present in an amount up to 2.0 wt.-%, preferably in the range of from 0.1 to .1 .0 wt.-%, and most preferably in the range of from 0.2 to 0.6 wt.-%, with respect to the total weight of the cementitious binder composition.

[0128] The cementitious binder composition according to claim 23, wherein the at least one dispersant is selected from the list consisting of polycarboxylate (PCE), preferably a methacrylate ester (MPEG), isoprenol ether (IPEG), or methallyl ether (HPEG) based PCE, polyhydric alcohol phosphate ester (PAE), and mixtures thereof.

[0129] The water-soluble polymeric dispersant preferably comprises at least two monomer units. It may also, however, be advantageous to use copolymers having three or more monomer units.

[0130] ‘Water-soluble polymers” in the sense of the present specification are polymers which in water at 20 °C under atmospheric pressure have a solubility of at least 1 g / l, more particularly at least 10 g / l, and very preferably of at least 100 g / l.

[0131] In one preferred embodiment, said at least one water-soluble polymeric dispersant comprises polyether groups of the structural unit (IV) BASF SE 240963W001

[0132] 12 B19191WO

[0133] *-U-(C(O))k-X-(AlkO)n-W (IV) where

[0134] * indicates the bonding site to the polymer,

[0135] U is a chemical bond or an alkylene group having 1 to 8 carbon atoms,

[0136] X is oxygen, sulfur or a group NR1, k is O or l , n is an integer whose average value based on the polymer is in the range from 3 to 300,

[0137] Aik is C2-C4alkylene, it being possible for Aik to be identical or different within the group

[0138] (Alk-O)n,

[0139] W is a hydrogen, a Ci-C6alkyl or an aryl radical or is the group Y F, where

[0140] Y is a linear or branched alkylene group having 2 to 8 carbon atoms and may carry a phenyl ring,

[0141] F is a 5 to 10 membered nitrogen heterocycle which is bonded via nitrogen and which as ring members, besides the nitrogen atom and besides carbon atoms, may have 1 , 2 or 3 additional heteroatoms, selected from oxygen, nitrogen, and sulfur, it being possible for the nitrogen ring members to have a group R2, and for 1 or 2 carbon ring members to be present in the form of a carbonyl group,

[0142] R1is hydrogen, C1-C4 alkyl or benzyl, and

[0143] R2is hydrogen, C1-C4 alkyl or benzyl.

[0144] With particular preference, the water-soluble polymeric dispersant of the invention comprises at least one group from the series of carboxyester, carboxyl, phosphono, sulfino, sulfo, sulfamido, sulfoxy, sulfoalkyloxy, sulfinoalkyloxy, and phosphonooxy group.

[0145] With more particular preference, the water-soluble polymeric dispersant of the invention comprises an acid group.

[0146] The term ‘acid group’ is understood in the present specification to refer both to the free acid and to the salts thereof. The acid may preferably be at least one from the series of carboxyl, phosphono, sulfino, sulfo, sulfamido, sulfoxy, sulfoalkyloxy, sulfinoalkyloxy, and phosphonooxy group. Particularly preferred are carboxyl and phosphonooxy groups.

[0147] In one particularly preferred embodiment, the water-soluble polymeric dispersant comprises a polycondensation product comprising

[0148] (V) a structural unit comprising an aromatic or heteroaromatic group and the polyether group, and

[0149] (VI) a phosphated structural unit comprising an aromatic or heteroaromatic group.

[0150] The structural units (V) and (VI) are preferably represented by the general formula (VII, VIII)

[0151] A-U-(C(O))k-X-(AlkO)n-W (VII) where

[0152] A is identical or different and is represented by a substituted or unsubstituted, aromatic or heteroaromatic compound having 5 to 10 carbons in the aromatic system, the other radicals possessing the definition stated for structural unit (IV); where BASF SE 240963W001

[0153] B19191WO

[0154] D is identical or different and is represented by a substituted or unsubstituted, aromatic or heteroaromatic compound having 5 to 10 carbons in the aromatic system,

[0155] E is identical or different and is represented by N, NH or O, m = 2 if E = N and m = 1 if E = NH or O,

[0156] R3, R4independently of one another are identical or different and are represented by a branched or unbranched Ci to C10 alkyl radical, C5to C8cycloalkyl radical, aryl radical, heteroaryl radical or H, preferably by H, methyl, ethyl or phenyl, more preferably by H or methyl, and especially preferably by H. Furthermore, b is identical or different and is represented by an integer from 0 to 300. If b = 0, E = O. More preferably D = phenyl, E = O, R3and R4= H, and b = 1 .

[0157] The polycondensation product preferably comprises a further structural unit (IX) where

[0158] Y independently at each occurrence is identical or different and is represented by (V), (VI) or further constituents of the polycondensation product.

[0159] R5, R6are preferably identical or different and represented by H, CH3, COOH or a substituted or unsubstituted, aromatic or heteroaromatic compound having 5 to 10 carbons. R5and R6here in structural unit (IX) are independently of one another preferably represented by H, COOH and / or methyl.

[0160] In one particular preferred embodiment, R5and R6are represented by H.

[0161] The molar ratio of the structural units (V), (VI), and (VII) in the phosphated polycondensation product of the invention may be varied within wide ranges. It has proven useful for the molar ratio of the structural units [(V) + (VI)]: (VII) to be 1 :0.8 to 3, preferably 1 :0.9 to 2, and more preferably 1 :0.95 to 1.2.

[0162] The molar ratio of the structural units (V): (VI) is normally 1 :10 to 10:1 , preferably 1 :7 to 5:1 , and more preferably 1 :5 to 3: 1 .

[0163] The groups A and D in the structural units (V) and (VI) in the polycondensation product are usually represented by phenyl, 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 2- methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, naphthyl, 2-hydroxynaphthyl, 4 hydroxynaphthyl, 2-methoxynaphthyl, 4-methoxynaphthyl, preferably phenyl, and A and D may be selected independently of one another and may also each consist of a mixture of the stated compounds. The groups X and E are represented independently of one another preferably by O.

[0164] Preferably, n in structural unit (IV) is represented by an integer from 5 to 280, more particularly 10 to 160, and very preferably 12 to 120, and b in structural unit (VI) is represented by an integer from 0 to 10, preferably 1 to 7, and more preferably 1 to 5. The representative radicals whose length is defined by n and b may consist here of uniform structural groups, though it may also be useful for them to comprise a mixture of different structural groups. Furthermore, the radicals of the structural units (V) and (VI) may independently of one another each have the same chain length, with n and b in each case being represented by one number. In general, however, it will be useful for these each to be mixtures having different chain lengths, and so the radicals of the structural units in the polycondensation product have different numerical values for n and, independently for b.

[0165] In one particular embodiment, the present invention further envisages a sodium, potassium, ammonium and / or calcium salt, and preferably a sodium and / or potassium salt, of the phosphated polycondensation product. BASF SE 240963W001

[0166] B19191WO

[0167] The phosphated polycondensation product of the invention frequently has a weight-average molecular weight of 5000 g / mol to 150 000 g / mol, preferably 10 000 to 100 000 g / mol, and more preferably 20 000 to 75 000 g / mol.

[0168] With regard to the phosphated polycondensation products for preferred use in accordance with the present invention, and to their preparation, reference is additionally made to patent applications WO 2006 / 042709 A1 and WO 2010 / 040612 A1 , the content of which is hereby incorporated into the specification.

[0169] In a further preferred embodiment, the water-soluble polymeric dispersant comprises at least one copolymer which is obtainable by polymerization of a mixture of monomers comprising

[0170] (X) at least one ethylenically unsaturated monomer which comprises at least one radical from the series of carboxylic acid, carboxylic salt, carboxylic ester, carboxylic amide, carboxylic anhydride, and carboxylic imide and

[0171] (XI) at least one ethylenically unsaturated monomer comprising a polyether group, the polyether group being represented preferably by the structural unit (IV).

[0172] The copolymers in accordance with the present invention contain at least two monomer units. It may, however, also be advantageous to use copolymers having three or more monomer units.

[0173] In one preferred embodiment, the ethylenically unsaturated monomer (X) is represented by at least one of the following general formulae from the group of (Xa), (Xb), and (Xc):

[0174] (Xa)

[0175] (Xb)

[0176] In the monocarboxylic or dicarboxylic acid derivative (Xa) and in the monomer (Xb) present in cyclic form, where Z = O (acid anhydride) or NR16(acid imide), R7and R8independently of one another are hydrogen or an aliphatic hydrocarbon radical having 1 to 20 carbons, preferably a methyl group. B is H, -COOMa, -CO-O(CqH2qO)r-R9, -CO-NH-(CqH2qO)r-R9.

[0177] M is hydrogen, a mono- or di- or trivalent metal cation, preferably sodium, potassium, calcium or magnesium ion, or else ammonium or an organic amine radical, and a = 1 / 3, 1 / 2 or 1 , according to whether M is a mono-, di- or trivalent cation. Organic amine radicals used are preferably substituted ammonium groups which derive from primary, secondary or tertiary Ci.2Oalkylamines, Ci.2Oalkanolamines, C5-8 cycloalkylamines, and C6-14 arylamines. Examples of the corresponding amines are methylamine, dimethylamine, trimethylamine, ethanolamine, diethanolamine, triethanolamine, methyldiethanolamine, cyclohexylamine, dicyclohexylamine, phenylamine, diphenylamine in the protonated (ammonium) form.

[0178] R9 is hydrogen, an aliphatic hydrocarbon radical having 1 to 20 carbons, a cycloaliphatic hydrocarbon radical having 5 to 8 carbons, an aryl radical having 6 to 14 carbons, this radical optionally being substituted as well, q = 2, 3 or 4 and r = 0 to 200, preferably 1 to 150. The aliphatic hydrocarbons here may be linear or branched and also saturated or unsaturated. Preferred cycloalkyl radicals are cyclopentyl or cyclohexyl radicals, and preferred aryl radicals are phenyl or naphthyl radicals, which in particular may also be substituted by hydroxyl, carboxyl or sulfonic acid groups. BASF SE 240963W001

[0179] 15 B19191WO

[0180] Furthermore, Z is O or NR16, where R16independently of each occurrence is identical or different and is represented by a branched or unbranched Ci to C10 alkyl radical, C5to C8cycloalkyl radical, aryl radical, heteroaryl radical or H.

[0181] The following formula represents the monomer (Xc):

[0182] In this formula, R10and R11independently of one another are hydrogen or aliphatic hydrocarbon radical having 1 to 20 carbons, a cycloaliphatic hydrocarbon radical having 5 to 8 carbons, an optionally substituted aryl radical having 6 to 14 carbons.

[0183] Furthermore, R12is identical or different and is represented by (CnH2n)-SO3H with n = 0, 1 , 2, 3, or 4, (CnH2n)-OH with n = 0, 1 , 2, 3, or 4; (CnH2n)-PO3H2with n = 0, 1 , 2, 3 or 4, (CnH2n)- OPO3H2with n= 0, 1 , 2, 3, or 4, (C6H4)-SO3H, (C6H4)-PO3H2, (C6H4)-OPO3H2and

[0184] (CnH2n)-NR14b with n = 0, 1 , 2, 3, or 4 and b by 2 or 3.

[0185] R13is H, -COOMa, -CO-O(CqH2qO)r-R9, -CO-NH-(CqH2qO)r-R9, where Ma, R9, q and r possess the definitions stated above.

[0186] R14is hydrogen, an aliphatic hydrocarbon radical having 1 to 10 carbons, a cycloaliphatic hydrocarbon radical having 5 to 8 carbons, an optionally substituted aryl radical having 6 to 14 carbons.

[0187] Furthermore, Q is identical or different and is represented by NH, NR15or O, where R15is an aliphatic hydrocarbon radical having 1 to 10 carbons, a cycloaliphatic hydrocarbon radical having 5 to 8 carbons or an optionally substituted aryl radical having 6 to 14 carbons.

[0188] In one particularly preferred embodiment, the ethylenically unsaturated monomer (XI) is represented by the following general formulae (Xia)

[0189] R8R7 in which all the radicals having the definitions above.

[0190] In a further-preferred embodiment, the ethylenically unsaturated monomer (XI) is represented by the following general formulae (Xlb) BASF SE 240963W001

[0191] 16 B19191WO

[0192] (XI b) where

[0193] R1, R2, R3independently of one another, identically or differently, are H, CH3,

[0194] R4is linear or branched C1-C30 alkylene,

[0195] R5, R6independently of one another, identically or differently, are H, C1-C20 alkyl, C3-C15 cycloalkyl, aryl, -CH2-O-C1-C20 alkyl, CH2-0-C2-C2o alkenyl, and R5and R6may also together form a C3-C6alkylene,

[0196] R7independently at each occurrence, identically or differently, is H, C1-C4 alkyl,

[0197] R8is C1-C22 alkyl, C2-C22 alkenyl, and n independently at each occurrence, is identical or different and is an integer from 2 to 200.

[0198] In particular, the copolymer has an average molar weight (Mw) of between 5000 and 150 000 g / mol, more preferably 10 000 to 80 000 g / mol, and very preferably 15 000 to 60 000 g / mol, as determined by gel permeation chromatography.

[0199] The polymers are analyzed for average molar mass and conversion by means of size exclusion chromatography (column combinations: Shodex OH-Pak SB 804 HQ and OH-Pak SB 802.5 HQ from Showa Denko, Japan; eluent: 80 vol% aqueous solution of HCO2NH4 (0.05 mol / l) and 20 vol-% MeOH; injection volume 100 pl; flow rate 0.5 ml / min).

[0200] The preparation of the comb polymers which comprise the structural units (X) and (XI) is carried out in a conventional way, for example by free-radical polymerization. It is, for example, described in EP 0 894 811 , EP 1 851 256, EP 2 463 314, EP 0 753 488.

[0201] The copolymer of the invention preferably fulfills the requirements of the industry standard EN 934-2 (February 2002).

[0202] Other additives

[0203] The cementitious binder composition according to the present invention may comprise further components such as aluminum hydroxide, rheology modifiers, defoamers, and / or air entrainers.

[0204] If the composition of the present invention is applied as a repair or tile adhesive system, it may further comprise Redispersible Polymer Powder, such as Vinyl Acetate-Ethylene (VAE), Acrylic Copolymers, or Styrene-Acrylic Copolymers, and / or cellulose ethers.

[0205] Building products

[0206] Suitable building products may include various types of concrete such as on-site concrete, finished concrete parts, pre-cast concrete components, cast concrete stones, concrete bricks, sprayed concrete (shotcrete), ready-mix concrete, air-placed concrete, and 3D printed concrete. Additionally, mortar, concrete repair systems, industrial cement flooring, one-component and two-component sealing slurries, screeds, filling and self-leveling compositions like joint fillers or self-leveling underlayments, adhesives (including building or construction adhesives, thermal insulation composite system adhesives, or tile adhesives), renders, plasters, sealants, coating and paint systems are also suitable. These are particularly useful for tunnels, wastewater drains, splash protection, and condensate lines. Other applicable products include dry mortars, sag-resistant, flowable or self-leveling mortars, drainage mortars, repair mortars, grouts (such as joint grouts, non-shrink grouts, tile grouts, windmill grouts, anchor grouts, flowable or selfleveling grouts), ETIC (external thermal insulation composite systems), EIFS (exterior insulation finishing systems) grouts, swelling explosives, waterproofing membranes, cementitious foams, and cementitious wall boards. BASF SE 240963W001

[0207] 17 B19191WO

[0208] Experimental Part

[0209] Measurement Methods a) Mortar strength

[0210] Mortar strength tests were conducted according to EN 196-1 , and samples were cured under water at 23.0 ± 1.0 °C (instead of 20.0 °C). One-time-use polystyrene molds with lids (according to DIN 1164) was used for the mortar bar casting instead of the steel molds. All the dry components, including the powder additives and standard sand, were weighed, and premixed in a bucket for 30 s in a shaking mixer (Skandex SK550 1.1) before the mortar mixing. The water / solid (w / s) ratio was 0.5 according to EN 196-1 , where solid refers to the final blended cement including limestone powder. The reported compressive strength was the mean of 4 values measured with 2 mortar bars according to the EN 196-1 standard. b) Mortar flow

[0211] Mortar flow table tests were conducted based on a standard mortar according to EN 196-1 by following the protocol described in EN 1015-3. 15 shocks were applied before the spread of the mortar was measured at 5, 15, and 30 min. After each measurement, the fresh mortar was kept in the mixing container and covered with a piece of wet cloth to avoid evaporation of the mixing water. c) Mortar setting

[0212] The mortar setting time was measured using automatic Vicat needles on the mortar sample prepared according to EN 196-1. The initial and final setting times were recorded. d) CO2footprint

[0213] Environmental impact of the mortar based on global warming potential (GWP, in the unit of kg CO2eq. / ton) were evaluated. The ‘Cradle to Gate’ GWP value corresponding to modules A1- A3 (as defined by EN 15804:2012+A2:2019 + AC:2021) was used for the production of the cement, SCMs including raw material extraction up to the finished product at the factory gate (cf. Table 1). To have a simple comparison, the system boundary for GWP does not include the processing of the final commercial mortar which involves dry mixing, packaging etc.

[0214] ‘Cradle-to-gate‘ product carbon footprint (PCF) data were used for the chemical additives (cf. Table 1). There is a wide range of reported GWP values for raw materials, which can be attributed to various factors such as different boundary conditions, energy makeups, different processes, and raw material sources. In the case of activated clay (i.e. calcined clay), due to its fast-developing nature, a long-term scenario with a GWP of 200 kg CO2eq. / ton was used.

[0215] The GWP for a binder mix design was calculated according to equation 3:

[0216] GWPbinder= wix GWPi(3) where

[0217] GWPbinderisthe final GWP for the binder mix design in kg CO2eq. / ton, wlis the weight fraction of the materials (binder or additive), and

[0218] GWP, is the A1-A3 GWP of the ithbinder component presented in kgCO2eq. / ton.

[0219] The performance-based specific GWP was calculated with the compressive mortar strength following equation 4: where

[0220] S_G WPjmortarare performance-based specific GWP at age j, with units of kg CO2eq. / (MPa ton dry mortar);

[0221] (jj is the compressive strength at age j unit in days, and BASF SE 240963W001

[0222] 18 B19191WO

[0223] 1350 and 450 are the grams of sand and binder solid in the standard mortar design, respectively.

[0224] Table 1. ‘Cradle-to-gate‘ GWP of the raw materials and additives. e) R3 of SCMs

[0225] A cement model paste is prepared by mixing 11.11 g of the supplementary cementitious material (SCM), 33.33 g of portlandite, 60 g of deionized water, 0.24 g of potassium hydroxide, 1 .20 g of potassium sulfate and 5.56 g of calcite. The heat release is recorded over the course of 7 days. The cumulative heat ‘Heat’) is calculated from 1.2 hours after the beginning of the calorimetry test onwards. The total heat release ‘Hrescaied“) is reported in J / (g SCM) as follows:

[0226] , , Heat

[0227] Hrescaled -(mpX0.0997)wherein

[0228] Heat is the cumulative heat in Joule and mpis the mass of the cement model paste in gram.

[0229] Examples

[0230] The compositions according to Table 3 were mixed and used for testing the properties of the resulting mortar compositions. Thereby, the materials as listed in Table 2 were used.

[0231] Table 2: Materials used in the examples

[0232] CE1 represents a classic Portland cement-based compositions having therefore typical parameters, such as very high CO2footprint, high late strength, low very early strength, large setting time windows and moderate spread loss. BASF SE 240963W001

[0233] 19 B19191WO

[0234] All other examples include SCMs to a certain degree thereby lowering the CO2footprint. Examples CE2 to IE2 are based on a composition having relatively low clinker phase (10 wt.-% CSA) and relatively high SCM content (37 wt.-%). Examples CE8 to IE6 are based on a composition having relatively high clinker phase (30 wt.-% CEM I and 5 wt.-% CSA) in combination with moderately high SCM content (27 wt.-%). Finally, Examples CE11 to IE10 are based on a composition having moderately high clinker phase (30 wt.-% CEM I) in combination with moderately high SCM content (32 wt.-%).

[0235] CE2 shows that without any ettringite formation controller or accelerator, a SCM based composition has the problem of high spread loss and low very early strength formation. Hence, the workability of the composition will significantly change the setting time window and at the same time the low very early strength does not allow for ideal further processing after setting.

[0236] Examples CE3 to CE7 show that it is not possible to achieve a balance of a high setting time window, a high very early strength, a high late strength and a low spread loss without combining an ettringite formation controller and an accelerator. It should be understood that IE1 and IE2 have lower contents of dispersant, as HyCon S 7042F, which comprises CSH nanoseeds, also comprises a dispersant, for the presence of which the lower amounts of dispersant compensate.

[0237] From the remaining examples it can be seen that increasing the cement clinker content allows for higher late strengths but also for higher very early strengths. Nevertheless, these compositions have the drawback of also increased CO2footprint.

[0238] 20 B19191WO

[0239] Table 3: Compositions and measurement results of the comparative and inventive examples.

Claims

BASF SE 240963W00121 B19191WOClaims1 . A cementitious binder composition comprising20-95 wt.-% of at least one supplementary cementitious material,0.01-59 wt.-% of at least one cement clinker,1-20 wt.-% of at least one sulfate source,0.5-30 wt.-% of at least one calcium and / or magnesium source,0.1-5 wt.-% of at least one soluble carbonate source, 0.001-3 wt.-% of at least one ettringite formation controller, and 0.001-5 wt.-% of at least one accelerator.

2. The cementitious binder composition according to claim 1 , wherein the cementitious binder composition comprises the at least one cement clinker in an amount in the range of from 5 to 50 wt.-%, preferably in the range of from 10 to 35 wt.-%, and most preferably in the range of from 28 to 32 wt.-%, with respect to the total weight of the cementitious binder composition.

3. The cementitious binder composition according to claims 1 or 2, wherein the at least one supplementary cementitious material is present in an amount in the range of from 21 to 80 wt.-%, preferably in the range of from 22 to 50 wt.-%, more preferably in the range of from 23 to 45 wt.-%, and most preferably in the range of from 25 to 30 wt.-%, with respect to the total weight of the cementitious binder composition.

4. The cementitious binder composition according to any of the preceding claims 1 to 3, wherein the at least one sulfate source is present in an amount in the range of from 1 to 18 wt.-%, preferably in the range of from 5 to 15 wt.-%, and most preferably in the range of from 8 to 12 wt.-%, with respect to the total weight of the cementitious binder composition.

5. The cementitious binder composition according to any of the preceding claims 1 to 4, wherein the at least one calcium and / or magnesium source is present in an amount in the range of from 1 to 20 wt.-%, preferably in the range of from 5 to 15 wt.-%, and most preferably in the range of from 8 to 12 wt.-%, with respect to the total weight of the cementitious binder composition.

6. The cementitious binder composition according to any of the preceding claims 1 to 5, wherein the at least one soluble carbonate source is present in an amount in the range of from 0.2 to 5 wt.-%, preferably in the range of from 0.5 to 3 wt.-%, more preferably in the range of from 0.7 to 1.5 wt.-%, and most preferably in the range of from 0.9 to 1.1 wt.-%, with respect to the total weight of the cementitious binder composition.

7. The cementitious binder composition according to any of the preceding claims 1 to 6, wherein the cementitious binder composition comprises at least one filler in an amount up to 20wt.-%, preferably in the range of from 5 to 20 wt.-%, more preferably in the range of from 15 to 20 wt.-%, and most preferably in the range of from 17 to 19 wt.-%, with respect to the total weight of the cementitious binder composition.

8. The cementitious binder composition according to any of the preceding claims 1 to 7, wherein the at least one ettringite formation controller is present in an amount in the range of from 0.1 to 2.0 wt.-%, preferably in the range of from 0.2 to 1.0 wt.-%, and most preferably in the range of from 0.3 to 0.6 wt.-%, with respect to the total weight of the cementitious binder composition.

9. The cementitious binder composition according to any of the preceding claims 1 to 8, wherein the at least one accelerator is present in an amount in the range of from 0.01 to 4.0 wt.-%, preferably in the range of from 0.5 to 3.0 wt.-%, and most preferably in the range of from 1 .0 to 2.0 wt.-%, with respect to the total weight of the cementitious binder composition.

10. The cementitious binder composition according to any of the preceding claims 1 to 9, wherein the at least one accelerator is selected from the list consisting of nanoseeds, preferably selected from C-S-H nanoseeds, silica nanoseeds, ettringite nanoseeds, calcium hydroxide nanoseeds, and mixtures thereof, thiocyanate, metal formate, metal sulfamate, sulfates, wherein the sulfates are preferably selected from sodium sulfate,BASF SE 240963W00122 B19191WO potassium sulfate, aluminum sulfate, and mixture thereof, nitrates, wherein the nitrates preferably are selected from sodium nitrate, potassium nitrate, calcium nitrate, magnesium nitrate, and mixtures thereof, calcium chloride, magnesium chloride, and mixtures thereof.11 . The cementitious binder composition according to any of the preceding claims 1 to 10, wherein the cement clinker is a crystalline and / or amorphous cement clinker in the range of CEM III to CEM IV, preferably is selected from the list consisting of Portland cement clinker (C3S, C2S, C3A, C4AF), calcium aluminate cement clinker (main phases CA, CI2A7, CA2, Q-phase), calcium sulfoaluminate cement clinker (main phases ye’elimite), alite sulfoaluminate cement clinker, belite ferrite sulfoaluminate cement clinker, and mixtures thereof, more preferably is selected from the list consisting of Portland cement clinker (C3S, C2S, C3A, C4AF), calcium aluminate cement clinker (main phases CA, CI2A7, CA2, Q-phase), calcium sulfoaluminate cement clinker (main phases ye’elimite), and mixtures thereof, even more preferably is selected from the list consisting of Portland cement clinker (C3S, C2S, C3A, C4AF), calcium sulfoaluminate cement clinker (main phases ye’elimite), and mixtures thereof, and most preferably is Portland cement clinker (C3S, C2S, C3A, C4AF).

12. The cementitious binder composition according to any of the preceding claims 1 to 11 , wherein the at least one supplementary cementitious material is a material, preferably powdered material, having an R3reactivity after 7 days of total heat release of equal to or more than 50 J / g SCM measured according to ASTM 1897, preferably wherein the at least one supplementary cementitious material is selected from the list consisting of activated clay, preferably calcined clay, ground granulated blast-furnace slag (GGBFS), electric arc furnace slag (EAF), basic oxygen furnace slag (BOF), fly ash, natural pozzolan, metakaolin, rice husk ashes, recycled concrete fine, perlite, zeolite, silica fume, or other synthetic and / or processed waste reactive materials.

13. The cementitious binder composition according to any of the preceding claims 1 to 12, wherein the at least one sulfate source is selected from the list consisting of calcium sulfate anhydrite, calcium sulfate hemihydrate, calcium sulfate dihydrate, sodium sulfate, potassium sulfate, aluminum sulfate, and mixtures thereof.

14. The cementitious binder composition according to any of the preceding claims 1 to 13, wherein at least one soluble carbonate is selected from the list consisting of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, amorphous calcium carbonate, vaterite, injected carbon dioxide, aqueous solution of carbon dioxide, or mixtures thereof.

15. The cementitious binder composition according to any of the preceding claims 1 to 14, wherein the at least one ettringite formation controller is glyoxylic acid, a glyoxylic acid salt, a glyoxylic derivative, sodium gluconate, alpha-sulfoglycolate, citric acid, salts of citric acid, tartaric acid, salts of tartaric acid, sugar, salts of sugar, phosphate, phosphonate, zinc oxide, and mixtures thereof, preferably is selected from an amine-glyoxylic acid condensate and an alpha-sulfoglycolate.

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